Sintered NdFeB permanent magnet is widely used because of its excellent magnet
property. But there is few report of machinbility of it. This paper presents an experimental
investigation of the machining characteristics of sintered NdFeB permanent magnet using a
combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). The
EDM / USM machining mechanisms are integrated to improve the machining efficiency. During the
experiments, concentration of abrasive in the dielectric fluid is changed to explore its effect on the
material removal rate (MRR). MRR of EDM /USM, conventional EDM and tool vibration aided
EDM are compared, REWR and machined surface characteristics are also compared between them.
From the experimental results, it is concluded that the combination EDM/USM process can increase
the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate
abrasive concentration can improve its machining efficiency.